Elastic, automatic, adjustable blasting-shell



R. L. BOWMAN.

ELASTIC, AUTOMATIC, ADJUSTABLE BLASTING SHELL.

APPLICATION FILED DEC-13, 1920.

Patented Au 30, 1921.

\iJiil WITNESSES ATTORNEYS UNITED srrss NT ()FFICE.

ELASTIC, AUTOMATIC, ADJUSTABLE BLASTING-SHELL.

Specification of Letters Patent. Patented Aug. 30, 1921.

Application filed December 13, 1920. Serial No. 430,420.

' T all whom-it may concern:

' a citizen of United'states, residing at Knoxville, Tennessee, have invented certain new and useful Improvements in Elastic, Automatic, Adjustable Blasting-Shells; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same:

This invention relates to blasting shells for blasting in coal mines, rock quarries, dirt and all other places where blasting powder is used; and particularly is adapted for coal mines where various size holes are drilled and different charges or quantities of powder are required to perform a given result.

The object of this invention is to provide a shell of such a character in which all the requirements of the miner of coal or the user of blasting powder are met in an ever-ready shell, whereby any differences in the size or depth of holes or the amount of powder needed for a certain shot are automatically arranged for in the construction of the shell.

With the foregoing and other objects in view the invention consists of certain novel features of construction and arrangement as will be more fully described and particularly pointed out in the appended claim, reference being bad to the accompanying drawings forming part of this specification, and in which:

Figure 1 is a side elevational view of one side of the shell;

Fig. 2 is a side elevation of the shell entirely opened;

Fig. 3 is a transverse sectional view of Fig. 2;

Fig. 4 is an elevational view of the shell adjusted to its next to maximum capacity and illustrating the expansion fold;

Fig. 5 is a transverse sectional view of Fig. 4:;

Fig. 6 is an elevational view, illustrating the shell adjusted to a minimum capacity; and

Fig. 7 is a transverse sectional view of Fig. 6.

. Referring to the drawings wherein for the sake of illustration is shown the preferred embodiment of the invention, the numeral 10 designates a seamless tube which constitutes the shell and which is constructed of suitable material, Qne face of the tube is provided with a series of graduations or calibrations, designated at 11 and which expresses in a suitable system of units the volume or contents of the shell and thus affords a means of determining the correct amount of powder to be used. Along one of its edges the tube is provided with a longitudinal plait or fold 12 which is bent back upon the body of the tube, the materlal of the tube being operated upon in any sultable manner to make the fold 12 a feature of the permanent construction of the tube so that the inherent elasticity of the tube resists deformation of the fold 12. This fold 12 thus constitutes an expansion fold which when the powder is tamped in the shell affords a means of permitting expansion against resilient resistance when such expansion is necessary to prevent rupture of the shell. Along its opposite longitudinal edge the tube is provided with a doubledback portion or fold 13 which provides for a slight decrease in the capacity of the shell when such is desired and intermediate its longitudinal edges the shell is provided with creases 14 which facilitate the folding of the tube from the position shown in Figs. 4 and 5 to the position shown in Figs. 6 and 7, in which latter position the tube has been adjusted to its minimum capacity. It is tobe noted that in all capacity adjustments of the tube the expansion fold 12 is retained and is operative to carry out its functions.

Various changes in the form, proportion, size and minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of the invention as defined in the claim hereto appended.

No two seams of coal or stratas are the same in structure; and different amounts of explosives are required to obtain the best results and when it is fully ascertained the amount necessary for a certain duty, it is highly essential to maintain an even and regular quantity in shooting that particular strata by having a well regulated shell that will adapt itself to the various conditions and sizes of holes that may arise.

It is an established fact that coal deposits are damaged by too heavy shots. The production is lessened by the time consumed in making the shell in the old way in the mines. Windy shots result from faulty non-adhesive shellsresulting in very little coal torn down, and i ven u other ways dangerous to the miner and the minescausing dead shots-involving extra labor in making a new shell and boring a new hole-all to be performed under the disadvantages of a low wall and in a cramped position of a coal mine. Then an adhesive shell that is not elastic is likewise objectionable because it most'always bursts from tamping and if in a wet or damp hole the result will be a hung shot,involving much extra. labor and the loss of time. The making of a shell requires skill which the inexperienced do not possess.

One of the objects of this invention is to provide ablasting shell so formed as to correspond with the minimum size of the hole or which can be instantly formed without the use of instrument or material to suit any size hole and yet at the same time to automatically adjust itself in expansion to the maximum size hole without bursting or splitting the shell.

Another object of this invention is to provide a blasting shell which will accurately measure the quantity of the explosive to be used. 7

Another object of this invention is to save time and material in constructing the shells, as well as to minimize the danger that might otherwise come to the miner or mines from the construction of a faulty, loose or baggy shell.

Having described-the invention what is claimed is:

A shell of the character described comprising a tube permanently doubled back upon itself along one of its longitudinal marginal edges to constitute an expansion fold and having a longitudinal crease extending from end to end of the tube and constituting a line of fold whereby the capacity of the shell may be varied. I

ROBERT LEE BOWMAN.

Witnesses:

J. S. DALLAS, H. A. AURIN. 

